1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 677d0362f334..80f9afcb1382 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -458,7 +458,11 @@ static int mei_ioctl_client_notify_request(struct file *file, u32 request)
 {
         struct mei_cl *cl = file->private_data;
 
-        return mei_cl_notify_request(cl, file, request);
+        if (request != MEI_HBM_NOTIFICATION_START &&
+            request != MEI_HBM_NOTIFICATION_STOP)
+                return -EINVAL;
+
+        return mei_cl_notify_request(cl, file, (u8)request);
 }
 
 /**